Not for the faint hearted.
I was genuinely surprised to see just how big these get, so if you're into really stretching yourself to the size of a finger, then this is the set for you. The stainless steel is much more comfortable to use than silicone rods. They feel solid and well made, the flat ends make them easy to hold and guide in without worrying about them slipping too far, and the handy case keeps them nice and easy to access (though the case itself does feel a little cheap). While the rods do start small, if you aren't planning on really stretching up to the larger sizes, you'd be better off getting a smaller set.